Had an immobiliser fault on my tvr s1 which has the old ford 2.8i from the capri (k-jetronic)

As I'm not so good with the squiggly amps I've just payed an auto electrician to remove the old immobiliser which was faulty. It now cranks over fine.

Hes said though its not sparking when the starter is cranking but would do when you stop cranking (e.g when the ignition is back a click).

There's a duraspark module on the bulkhead that I haven't got a clue what it does, could this be faulty?

What could I have wired up wrong to rob current from the coil circuit during cranking or are there any modules that could be faulty.

Assuming the guy did a good job of taking the immob out. It use to kill the starter but no the fuel pump so I assumed the second circuit it cut was something to the ignition circuit, is there a poss he hasn't connected that back up right?

Help before this starts to cost me £s

[Edited on 22/4/09 by mikeb]

check that the starter bypass wire to the coil is connected. If the ballast resister is only connected, then the current will flow only on the ignition postion but not the cranking position, you'll get no spark and the engine will die the instant you stop cranking - see diagram below, near the ignition switch






[Edited on 22/4/09 by Mr Whippy]

thanks wippy my comp isn't showing the picture though

link to my wiring diagram,

http://www.tvrsseries.com/drawings/tvrswiringdiagrama4.pdf

if you can tell me which bit to look fro on here it would help.

Just a thought I did try the wires to the starter motor both ways round if I have them the wrong way round would it still crank but not spark, one does seem to go to the coil

[Edited on 22/4/09 by mikeb]

refresh the screen and the pic will show

Look at the ignition switch on the diagram and follow the wires from ignition switch terminal 50 with a highlighter and you see the ballast resister (noted as 'thick BR' is connected to the ignition position on the switch and infact it looks like the starter bypass feed is actually coming from the starter motor solenoid! as a BG wire into the ignition module, so that the one that’s missing...I think

[Edited on 22/4/09 by Mr Whippy]

on the second diagram bottom left hand side, it's the BY wire from the srarter motor to the cold start resistor.

If I remember correctly.

Dave

[Edited on 22/4/09 by need4speed]

should BY give 12v during cranking? or at ignition on

Any thoughts if I connected the terminals on the starter the wrong way round would it make a difference?

[Edited on 22/4/09 by mikeb]

The starter solanoid should have a 12v supply that is only live when cranking.

this 12v supply is also fed from the starter solanoid to the coil - missing out the balast resitor. But this feed wire will only be live when cranking.

normally another feed wire to the coil supplies a lower voltage because of the resistance of the thicker ( special ) feed wire.

I think thats what they are on about ---BUT dont take my word for it

traced all the wiring back, everything looks like its connected up as per the diagram and in good condition. I cleaned most connectors etc in the process as they were a little corroded.

Begining to think the duraspark box is at fault, it was sat outside for 4 years or so on the bulk head of the car, which may have been exposed to the elements.

What voltages should one expect at the coil +ve at ignition on and during cranking if the lead is disconnected from the coil? From what I could work out it dropped a couple of volts during cranking.

If it's a 6v coil with balast resistor then ignition on you should see 6V ish, but during cranking will be nearer 12V.